“Usually you’re looking at faint little blob. But when I saw it moving … that was quite a feeling,” said MartinDurant, an astrophysicist at the University of Toronto whose study of the Vela pulsar was published last week in The Astrophysical Journal.

According to Durant, pulsars like the Vela — a star with a diameter the size of about 176 football fields that is the remnants of a massive star that exploded more than 10,000 years ago — have long intrigued researchers for their extreme environments, with high-energy particles and powerful magnetic fields.

As he noted in a recent blog post, “they have more mass than the sun, squeezed into a ball the size of a city, making them denser than the nucleus of an atom.”

Durant said researchers may be able to use pulsars, which present such extremes, to better understand stable patterns on Earth.

When he first began his research on the Vela pulsar in 2009, Durant said, the team believed there was movement in the jet of particles that races along the star’s rotation axis.

But the latest video, captured as a sequence of images by NASA’s Chandra X-ray Observatory telescopebetween 2009 and 2010, has researchers feeling more confident that the pulsar is actually wobbling like a spinning top, an effect called “free precession” that indicates movement without any external force.

Apart from academic curiosity, Durant said, the movement shown in the Vela pulsar now gives scientists a focus in their search for the elusive gravitational waves, described as “space-time ripples,” that were first predicted by Albert Einstein’s theory of general relativity.